The advent of modern bonding materials used in dentistry has brought with it the problem of eye exposure to the resin curing lights. These types of curing lights emit wave lengths that have been shown to be damaging to the human eye. The need for protective apparatus for both the physician and assistant staff members has been recognized. The protective devices employed in the past include light-filtering lenses, either worn over the eyes in the form of eyeglasswear or small hand-held instruments that are held close to the region to the tooth being cured. The dangerous range of UV output that has been identified is in the 400 to 525 nanometer range.
Prior art examples of hand-held light filtering instruments have had the disadvantages of; being too small for the patient to hold, not filtering the proper wave lengths of light sufficiently, not being able to be sterilized in a commonly used disinfectant, not providing any additional magnification and not adequately filtering the intensity of the light transmitted through the filter.
In addition to the problems with prior art protective filtering devices, there are several additional needs which have not been met. Shielding the eyes with eyeglasswear requires a separate set of glasses for each individual present in the operatory. This results in the increased cost of requiring many pairs of protective eyewear as well as the inconvenience and discomfort to other staff members. There is a need for a single, inexpensive unit which provides protection for all of the type described in the present application. Furthermore, tests have shown that after approximately 2 minutes of use of the tinted eye shield devices, the physician's eyes become color distorted and require color correcting. The remedy for providing the necessary color correction is for the physician to concentrate his vision on a light blue color source which, after a few seconds, will correct his vision for color. Heretofore, there has not been a convenient source of the light blue color correcting object and this is provided in the instant invention as a colored portion on the hand-held filtering instrument itself which, of course, is present at exactly the times when the physician would require vision color correcting.